A Peculiar Conversation
One day, Eric and Frederick is trying to figure out Greg's birthday, which is one of the dates listed above.
Greg told them that his birthday is indeed one of the dates listed above. He then told Eric and Frederick the month and the day of his birthday respectively.
The following conversation took place:
Eric: I don't know Greg's birthday.
Frederick: At first I don't know when Greg's birthday is, but I know now.
Eric: Then I also know when Greg's birthday is.
When is Greg's birthday?
Assume everyone is perfectly logical and speaks the truth.
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1 solution
The way I solved this was kind of strange. This was the first time I had encountered a problem like this, so it was kind of cool. :) Anyway, if person A only knew the month, then it could have either been May 1st or May 2nd, otherwise he would have known for a fact that June 1st was the birthday (since it was the only June birthday given.) If person B only knew the date, then it could have been either May 1st or June 1st, since otherwise May 2nd would have been the obvious choice. So, basically, we knew that it was on a 1st and it was a May birthday. Answer: May 1st.